Preservation of comestibles



April 25, 1944. F. KIEFER PRESERVATION OF COMESTIBLES Original FiledSept. 11, 1939 INVENTOR. 4 Q 1 6/! Patented Apr. 25, 1944 OFFICEPRESERVATION OF COMESTIBLES Felix Klefer, Flushing, N. Y.

Original application September 11, 1939, Serial No. 294,225. Divided andthis application May 23, 1942, Serial No. 444,180

Claims. (Cl. 99-150) This invention relates generally to preservation ofcomestibles. It relates more particularly to the treatment of productssubject to oxidative deterioration and still more particularly to thetreatment of comestibles susceptible to change resulting in rancidity.

This application is a division of my copending application, Serial No.294,225, filed September 11, 1939, in which said copending applicationis disclosed various procedures for inhibiting rancidification ofcomestibles.

As pointed out in my said copending application, Serial No. 294,225, itis known that many compositions of matter, including variouscomestibles, turn rancid. This is particularly true of the food productscontaining fats or fat-like substances which undergo oxidativedeterioration.

I have found that active hydrogen may be caused to react with therancid-forming substances with resulting inhibition and retardation, orcomplete elimination of the undesirable oxidative deterioration of foodproducts. This invention, therefore, comprehends a process and apparatusfor the treatment of comestibles to inhibit rancidification.

My researches lead me to believe that the reaction of active hydrogenmay find its explanation in the chemical changes which therancid-forming substances undergo when they become rancid. As mentionedin the foregoing, rancidity is believed to be the result of oxidatlvechange generally characteristic of fats and more frequently of such fatswhich, in their chemical structure, contain one or more unsaturatedgroups marked by double-bonds. Rancidity is preceded by an inductionperiod during which oxygen is absorbed by the material without anysubstantial chemical reaction taking place at the outset.

The next step is marked by the combination of oxygen with the compoundscontaining the unsaturated link with consequent formation of a peroxideor ozonide. This step may take place under the influence of one or morecatalysts which may be of an organic or inorganic nature, such asso-called enzymes, or certain metals or metal salts. Or, it may bebrought about by chemically active light, such as ultraviolet, which isalso part of the sunlight.- Owing to the deleterious efiect of activelight, it has been common practice to protect products liable tooxidative deterioration by packaging them, with the purpose of keepingthem in the dark or to shield them from the active light.

The peroxides and ozonides are very unstable and break apart where theoxygen addition has taken place. The ultimate result is that aldehydes,ketones and fatty acids are formed as fragments of the original fat.These, unlike the pure fats, are characterized by the odors and tastestypical of rancidity.

A somewhat difierent process may take place in the presence of certainbacteria which produce hydrolizing of the fat, i. e. breaking it apartinto fatty acids and glycerin of which it is composed. These fatty acidsthus formed may then also undergo oxidative deterioration as suggestedabove.

From the foregoing brief explanation of the rancidification of a fat, itmay be postulated where inhibitive action should set in, in order to beeffective. It is, first, at the compound itself, 1, e. at itsunsaturated links where it may add on oxygen; and, second, at thosecatalytic agents which would act as helpmates of the oxygen in itsdestructive action.

A still further approach, which, however, serves only in specific cases,is to destroy the bacteria heretofore mentioned in order to inhibit anylipolytic action originating indirectly from them.

With the foregoing in view, I aim according to the invention to cause areaction between the rancid-forming substances whereby they may becomestable against undesirable combination with oxygen. To accomplish thedesirable results comprehended by the invention, I treat the productscontaining the rancid-forming substances with active hydrogen in orderto bring about the desired reaction.

I believe further that when active hydrogen is brought into contact withsome of the products which are subject to such oxidative deteriorationas hereinbefore mentioned, it launches a severe attack at the catalyticagencies present in the deteriorative product; first, by reacting withsubstantially every trace of oxygen adsorbed in it; and, second, byreacting in certain cases with the catalysts themselves. Thus, thecatalysts are rendered impotent to perform their usual function.

I have set forth an hypothesis for a theoretical explanation underlyingmy invention, and it will be understood that it is what I presentlybelieve in the light of my researches. But whatever conclusion may bereached as to the possible mechanism, chemical, physical or both,involved, my invention comprehends the-protective and preserving effectof the treatment of compositions of matter with active hydrogen toinhibit, retard or entirely eliminate oxidative deterioration orransidification.

It will be understood in this connection that the term active hydrogen"is intended to connote that form of hydrogen in which it can reactdirectly with other elements or substances. While it is somewhat amatter of academic debate or discussion, it has been mostly identifiedwith nascent hydrogen and with atomic hydrogen. But the various ways inwhich investigators have arrived at the form of active hydrogen issuggested by a number of different designations formulated as follows:H, H H2 Ha.

Nascent hydrogen or hydrogen ion is obtained, for example, when hydrogenis generated by chemical decomposition, such as from iron andhydrochloric acid. Atomic hydrogen is formed, for example, whenmolecular hydrogen is bombarded with electrons or active rays, wherebyto break apart the molecules. The other forms may be more a matter ofspeculation; H2+ having been assumed to exist near the cathode in a lowvoltage discharge tube. H: has been considered as a rearrangementproduct of hydrogen under high voltage discharge at moderate vacuum. Itis so written because of its resemblance, as to high reactivity, toozone.

As further pointed out in my said copending application, Serial No.294,225, the invention lends itself to the treatment of comestibles invarious apparatuses. This application is directed more particularly tothe treatment of comestibles by bringing them into reactive contact withactive hydrogen formed by subjecting hydrogen gas to various forms ofelectric discharges.

Although'the novel features which are believed to be characteristic ofthis invention will be particularly pointed out in the claims appendedhereto, the invention itself, as to its objects and advantages, and themanner in which it may be carried out, may be better understood byreferring to the description with reference to certain of the followingexamples taken in connection with the accompanying drawing forming apart hereof, in which Fig. 1 is a view in elevation of a glass electricdischarge apparatus in which the invention may be practiced; and Fig. 2is a view in elevation of a different form of electric dischargeapparatus in which the invention may be practiced.

The following examples are illustrative of the manner of practicing theinvention.

Example I This example describes the stabilization treat ment applied totoasted wheat flakes after manuiacture in the ordinary manner whereinthe toasted cereal is brought into reactive contact with active hydrogenprepared from hydrogen gas by exposing it to an electric discharge in amodifled Geissler tube (vacuum discharge tube) such as shown in Fig. 1.

The toasted and dried wheat flakes designated 20 (Fig. 1) were placed inan upper chamber 2| connected with a tube 22 providing a discharge zone23. Suitable aluminum electrodes 24 and 25 were connected through aluminous tube transformer (not shown) of 9000 volts and 30 milliamperesoutput, which in turn received its current from a 110 v. A. C. 60 cyclecircuit. A hydrogen gas inlet 26 is located near the bottom end of tube22 and connected to a suitable source (not shown) of hydrogen gas. A gasoutlet port 21 is connected to a suction pump (not shown) to produce apartial vacuum in the electric discharge zone 23. A collecting chamber28 for treated product (designated 2IT) isconnected to the lower end oftube 22.

Toprocess the material 23, discharge zone is i put under high vacuum(1-10 mm. Hg, residual pressure) and flushed twice or three times withhydrogen. After this, the hydrogen flow is reduced to a volume tomaintain the vacuum indicated. Current is caused to flow through the.electrodes 24 and 25 to provide the electric dis- Example II In orderto treat cereal such as toasted wheat flakes with a higher moisturecontent, and yet to maintain a high vacuum in the discharge zone, amodified form of apparatus may be employed, such, for example, as thatshown in Fig.2. It is characterized by two large stop cocks, a feederstop cock 30 positioned near the upper end of the apparatus, and areceiver stop cock 3| near the lower end. A tube 32 is connected withthe stop cocks and is provided with an aluminum electrode 33 near itslower end and an aluminum electrode 34 near its upper end. Theelectrodes are connected to a suitable source of current through atransformer (not shown) as described in the foregoing. The upper stopcock 30 is connected to a material supply chamber 35 and the lower stopcock 3| is connected to a receiving chamber 36 for treated material. Thefeed chamber 35 is normally closed by a stopper 31. It is provided withan hydrogen inlet port 38 and an outlet port 39 which may be connectedto a suction pump (not shown).

Near the lower end of tube 32 is provided a hydrogen gas feed port 40,which may be connected to a suitable source of hydrogen (not shown). Theupper end of the tube 32 is provided with an expanded part providing asurge chamber 4| to which the electrode 34 is connected. The chamber 4|is also provided with a gas outlet port 42 which may be connected with asuction pump (not shown). Stop sock 3D is provided with a feed cup 43,and stop cock 3| with a receiving cup 44.

This device may be operated as follows: Material 45 to be treated isplaced in the chamber 35 and closed by the stopper 31. Chamber 35 may beflushed with hydrogen gas through inlet port 38 and then put andmaintained under vacuum.

Hydrogen gas is passed into tube 32 through port 40 and the dischargezone 46. The tube is maintained under vacuum as described in theforegoing. Suitable current is passed through the electrodes 33 and 34,thus to provide the electric discharge zone. A quantity of materialunder vacuum is collected in the feeding cup 43 from which it may betransferred under vacuum to the discharge zone 46 by turning the stem ofstop cook 30. Thus there is provided a transfer mechanism from thecharging chamber under vacuum to the vacuum tube where it is caused topass through the discharge zone into reactive contact with the activehydrogen therein. The treated material may be collected in receiving cup44 from whence it may be transferred to the receiving chamber 35 for thetreat vacuum in the discharge tube 32. If desired, the receiving chamber36 may be maintained under vacuum by means of stopper 4! and ports 48and 49 connected to a suitable source of vacuum.

This apparatus has been successfully used for the treatment not only ofcereal flakes to improve stabilization against rancidification, but alsofor the treatment to improve the stability of dry milk and groundroasted coffee.

- Example III A quantity of whole dry milk (powdered milk), which due toexposure to heat and atmospheric oxygen had assumed a noticeable butteryodor, was passed through the vacuum discharge tube containing anatmosphere of hydrogen, according to a procedure described in theforegoing. After this treatment. the odor of the milk was restored toits original freshness and was maintained over a long storage period.

It will be seen from the foregoing description that my invention asdisclosed in this application comprehends the treatment of comestiblesand the like, which contain rancid forming substances, by bringing theminto reactive contact with hydrogen rendered active by subjecting it totreatment in an electric discharge zone.

While certain novel features of the invention have been disclosedherein, and are pointed out in the annexed claims, it will be understoodthat various omissions, substitutions and changes may be made by thoseskilled in the art without departing from the spirit of the invention.

What is claimed is:

1. In a process of preserving from oxidative deterioration toastedcereal flakes containing substances susceptible of turning rancid, thestep which comprises contacting said toasted flakes with an activehydrogen which has been rendered active in an electric discharge zoneunder partial vacuum, to cause a reaction between said active hydrogenand the rancid forming substances in said flakes to inhibit subsequentoxidative deterioration of said cereal flakes.

2. In a process of preserving from oxidative deterioration a comestiblein form of solid particles containing substances susceptible of turningrancid, the method which comprises main- I 7,436.51 ed product withoutmaterially disturbing the, I

taining an electric discharge zone under partial vacuum, maintaining insaid zone hydrogen gas whereby to produce active hydrogen and contactingthe active hydrogen with said solid particles.

3. In a process of preserving from oxidative deterioration dried milkcontaining substances suscepticle of oxidative deterioration, the methodwhich comprises maintaining an electric discharge zone under partialvacuum, passing hydrogen gas through said zone whereby to produce activehydrogen, and causing said dried milk to pass through said zone incontact with the active hydrogen, whereby to cause said active hydrogento react with said substances to inhibit subsequent oxidativedeterioration of the cornestible.

4. A process of preserving from oxidative deterioration a comestiblecomposition of matter in the form of solid particles containingsubstances susceptible of oxidative deterioration which comprisespassing hydrogen gas through a. zone maintained under a vacuum of from 1to 10 mm. of mercury wherein is provided electric discharges to rendersaid hydrogen active, causing the comestible to'pass through said zonein reactive contact with the hydrogen rendered active and out of contactwith electrodes whereby to cause rancid forming substances in saidcomestiblc to react with said active hydrogen thereby to produce saidcomestible in a form which preserves it from oxidative deterioration andthen collecting the comestible after it has been passed through saidelectric discharge zone.

5. A process of preserving from cxidative deterioration a ground roastedcoffee containing substances susceptible of oxidative deteriorationwhich comprises passing hydrogen gas through a zone maintained underpartial vacuum wherein is provided electric discharges to render saidhydrogen active, causing the ground cofiee to pass through said vacuumzone in reactive contact with the hydrogen rendered active and out ofcontact with electrodes whereby to cause rancid forming substances insaid coffee to react with said active hydrogen thereby to produce saidcofiee in a form which preserves it from oxidative deterioration andthen collecting the c'ofl'ee after it has been passed through saidelectric discharge zone.

FELIX KIEFER.

